A solid electrolyte capacitor, which has an aluminum electrode coated with a dielectric film, and a compound which has a siloxane compound applied to this dielectric film, is known from U.S. Pat. No. 6,483,694 B1. That siloxane compound is intended to improve the adhesion between the dielectric film and electrically conductive polymers still to be applied. The disadvantage of a solid electrolyte capacitor of this type is, however, that it has a reduced capacitance.